Inherited thrombocytopenias frequently diagnosed in adults.

The diagnosis of inherited thrombocytopenias is difficult for many reasons. First, as all rare diseases, they are little known by clinicians who, therefore, tend to suspect the most common forms. Secondly, making a definite diagnosis often requires complex laboratory techniques that are available only in a few centers. Finally, half of patients have forms that have not yet been described. As a consequence, many patients with inherited thrombocytopenias are misdiagnosed with immune thrombocytopenia and are at risk of receiving futile treatments. Misdiagnosis is particularly frequent in patients whose low platelet count is discovered in adult life, because in these cases even the inherited origin of thrombocytopenia may be missed. Making promptly the correct diagnosis is important since we recently learned that some forms of inherited thrombocytopenia predispose to other illnesses, as leukemia or kidney failure, and affected subjects therefore require close surveillance and, if necessary, prompt treatments. Moreover, medical treatment can increase platelet count in specific disorders, and affected subjects can therefore receive drugs instead of platelet transfusions when selective surgery is required. In this review we will discuss how to suspect, diagnose and manage inherited thrombocytopenias, with particular attention to the forms that frequently present in adults. Moreover, we describe four recently identified disorders that belong to this group of disorders often diagnosed in adults: MYH9-related disease, monoallelic Bernard-Soulier syndrome, ANKRD26-related thrombocytopenia and familial platelet disorder with predisposition to acute leukemia.